Why do you think cloning in plants is stable(tissue cultured) but not consistent in animals?

Plant cells are less complex than animals,. May i know your specific opinions on : why cloned animals don't have normal life time n all other features as their normal counterparts, where as cloned plants do.. Thank You very much =)

Mar 26 2012:
In nature it is quite common for plants to spontaneously clone themselves. A fallen branch of a frangipani or a segment from a cactus will spontaneously grow roots and form a new plant. This sort of behaviour is only seen in relatively simple animals like jellyfish or sea stars. The closest you will get to a natural clone in a vertebrate is some lizards that produce offspring by parthenogenisis. Due to this natural cloning plants retain the ability. Any cloned vertebrate is being asked to do something that its ancestors lost the ability to do hundreds of millions of years ago.

Mar 25 2012:
I would suspect it is either due to the fact that the animal DNA structure is much more complex than DNA of a plant or that a animal clone's metabolism is rate is burn energy at a rate that burn it's life much faster. Well that's my guess, this really isn't the type of science I but my I'll give it a second look and see what i come up with.

Mar 25 2012:
Thank You very much Jamal =)
Well I found few,
1. DNA methylation variation in cloned mice - Genome variation* [this paper is very specific n awesome =) ]
2. Abnormal Up regulation and Down regulation of Protein from embryo stage itself - Proteome Variation**
3. Ur suspicion on rate of metabolism is also correct =) But the other way in maximum cases- the metabolic rate of cloned animals from embryonic to adult stage is low compared to normal animals.***
> The above stuffs create abnormal fetal development and the consequences follow.. cont'd..

Mar 25 2012:
Yeah, during a lecture I got this doubt n asked my Prof. His opinion was perhaps during evolution animals got complex biological system which makes them hard to compromise in the process like cloning than Plants..
Though its the cell structure and Organization that make the difference, I want to know specifically how ?
Am searching,. will find soon =) Thank You very much =)